Nikos Baxevanis
I’m currently doing security research at the Stacks Foundation, with a focus on smart contract fuzzing and analyzing the security of the Stacks blockchain node implementation. My work spans fuzzing consensus-critical components such as the PoX smart contract and designing tools for systematic vulnerability discovery.
More broadly, I build testing tools for smart contracts and functional programming languages. I’m especially interested in property-based testing, pseudorandom generators, and the design of expressive APIs that promote correctness by construction.
Projects
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2022 - present
Property-based testing, fuzzing, and invariant testing for smart contracts that run on the Stacks 2.x layer-1 blockchain with Pandora, eventually released as Rendezvous, co-authored with Radu Bahmata. -
2016 - present
Early contributor and now maintainer of Hedgehog, a state-of-the-art property-based testing system in the spirit of QuickCheck, for Haskell, F#, R, and Scala. Originally created by Jacob Stanley, whose ideas continue to influence the project. -
2017 - 2021
Doctest, helps you test interactive F# examples, similar to doctest in Python. Built primarily as an internal tool for Hedgehog. -
2017 - 2020
Pure Haskell and F# implementation of SplitMix, splittable pseudorandom number generator. Port of Guy L. Steele, Jr., Doug Lea, Christine H. Flood Fast splittable pseudorandom number generators Comm ACM, 49(10), Oct 2014, pp453-472. Passes all dieharder tests. -
2016 - 2017
Write you some QuickCheck, a minimal, POC, version of QuickCheck v1 ported in F#. -
2011 - 2020
Fare, allows you to generate random text that is guaranteed to match a regular expression passed in. Port of dk.brics.automaton DFA/NFA implementation and xeger. -
2011 - 2019
One of the oldest contributors to AutoFixture, a testing system that helps you write more compact, maintainable, unit tests.
Posts
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2023-01-16 - Pandora
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2022-03-15 - Clarity model-based testing primer
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2022-03-05 - Clarity property-based testing primer
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2020-03-30 - The rhyme of the altered Parser
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2017-04-10 - Less fragmented properties with Hedgehog
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2016-02-08 - Write you some QuickCheck
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2015-09-25 - Regex-constrained strings with FsCheck
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2014-02-13 - Levels of open-source code
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2011-11-19 - Notes from porting Java code to .NET
Quotes
“One of the best developers I've ever worked with is @nikosbaxevanis. Please don't steal him from my team!”
--Mark Seemann, author of Dependency Injection Principles, Practices, and Patterns
“Solid development skills. When Nikos submits a pull request, it is a cold day in hell that it doesn't work.”
--Kevin Bennett, co-founder and CTO of KBMax
“I learned a huge amount from Nikos, especially about F# programming and the more advanced aspects of unit testing.”
--Mike Hadlow, freelance software consultant and blogger